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Merge pull request #27 from mpnovikova/bignum
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Refactored number parsing
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@creationix
creationix committed Oct 8, 2015
2 parents 62ca604 + 5245aa6 commit 044b268
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Showing 2 changed files with 52 additions and 147 deletions.
190 changes: 46 additions & 144 deletions jsonparse.js
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Original file line number Diff line number Diff line change
Expand Up @@ -27,13 +27,7 @@ var NULL1 = C.NULL1 = 0x41;
var NULL2 = C.NULL2 = 0x42;
var NULL3 = C.NULL3 = 0x43;
var NUMBER1 = C.NUMBER1 = 0x51;
var NUMBER2 = C.NUMBER2 = 0x52;
var NUMBER3 = C.NUMBER3 = 0x53;
var NUMBER4 = C.NUMBER4 = 0x54;
var NUMBER5 = C.NUMBER5 = 0x55;
var NUMBER6 = C.NUMBER6 = 0x56;
var NUMBER7 = C.NUMBER7 = 0x57;
var NUMBER8 = C.NUMBER8 = 0x58;
var STRING1 = C.STRING1 = 0x61;
var STRING2 = C.STRING2 = 0x62;
var STRING3 = C.STRING3 = 0x63;
Expand All @@ -55,14 +49,6 @@ function Parser() {
this.string = undefined; // string data
this.unicode = undefined; // unicode escapes

// For number parsing
this.negative = undefined;
this.magnatude = undefined;
this.position = undefined;
this.exponent = undefined;
this.negativeExponent = undefined;
this.numberLength = 0;

this.key = undefined;
this.mode = undefined;
this.stack = [];
Expand All @@ -83,7 +69,7 @@ Parser.toknam = function (code) {
if (C[key] === code) { return key; }
}
return code && ("0x" + code.toString(16));
}
};

var proto = Parser.prototype;
proto.onError = function (err) { throw err; };
Expand All @@ -108,15 +94,14 @@ proto.write = function (buffer) {
}else if(n === 0x66){ this.tState = FALSE1; // f
}else if(n === 0x6e){ this.tState = NULL1; // n
}else if(n === 0x22){ this.string = ""; this.tState = STRING1; // "
}else if(n === 0x2d){ this.negative = true; this.tState = NUMBER1; // -
}else if(n === 0x30){ this.magnatude = 0; this.tState = NUMBER2; // 0
}else if(n === 0x2d){ this.string = "-"; this.tState = NUMBER1; // -
}else{
if (n > 0x30 && n < 0x40) { // 1-9
this.magnatude = n - 0x30; this.tState = NUMBER3;
if (n >= 0x30 && n < 0x40) { // 1-9
this.string = String.fromCharCode(n); this.tState = NUMBER3;
} else if (n === 0x20 || n === 0x09 || n === 0x0a || n === 0x0d) {
// whitespace
} else {
return this.charError(buffer, i);
return this.charError(buffer, i);
}
}
}else if (this.tState === STRING1){ // After open quote
Expand Down Expand Up @@ -180,131 +165,48 @@ proto.write = function (buffer) {
} else {
return this.charError(buffer, i);
}
}else if (this.tState === NUMBER1){ // after minus
n = buffer[i];
this.numberLength++;
if (n === 0x30) { this.magnatude = 0; this.tState = NUMBER2; }
else if (n > 0x30 && n < 0x40) { this.magnatude = n - 0x30; this.tState = NUMBER3; }
else {
return this.charError(buffer, i);
}
}else if (this.tState === NUMBER2){ // * After initial zero
n = buffer[i];
this.numberLength++;
if(n === 0x2e){ // .
this.position = 0.1; this.tState = NUMBER4;
}else if(n === 0x65 || n === 0x45){ // e/E
this.exponent = 0; this.tState = NUMBER6;
}else{
this.tState = START;
this.onToken(NUMBER, 0);
this.offset += this.numberLength - 1;
this.numberLength = 0;
this.magnatude = undefined;
this.negative = undefined;
i--;
}
}else if (this.tState === NUMBER3){ // * After digit (before period)
n = buffer[i];
this.numberLength++;
if(n === 0x2e){ // .
this.position = 0.1; this.tState = NUMBER4;
}else if(n === 0x65 || n === 0x45){ // e/E
this.exponent = 0; this.tState = NUMBER6;
}else{
if (n >= 0x30 && n < 0x40) { this.magnatude = this.magnatude * 10 + n - 0x30; }
else {
this.tState = START;
if (this.negative) {
this.magnatude = -this.magnatude;
this.negative = undefined;
}
this.onToken(NUMBER, this.magnatude);
this.offset += this.numberLength - 1;
this.numberLength = 0;
this.magnatude = undefined;
i--;
}
}
}else if (this.tState === NUMBER4){ // After period
n = buffer[i];
this.numberLength++;
if (n >= 0x30 && n < 0x40) { // 0-9
this.magnatude += this.position * (n - 0x30);
this.position /= 10;
this.tState = NUMBER5;
} else {
return this.charError(buffer, i);
}
}else if (this.tState === NUMBER5){ // * After digit (after period)
n = buffer[i];
this.numberLength++;
if (n >= 0x30 && n < 0x40) { // 0-9
this.magnatude += this.position * (n - 0x30);
this.position /= 10;
}
else if (n === 0x65 || n === 0x45) { this.exponent = 0; this.tState = NUMBER6; } // E/e
else {
this.tState = START;
if (this.negative) {
this.magnatude = -this.magnatude;
this.negative = undefined;
}
this.onToken(NUMBER, this.negative ? -this.magnatude : this.magnatude);
this.offset += this.numberLength - 1;
this.numberLength = 0;
this.magnatude = undefined;
this.position = undefined;
i--;
}
}else if (this.tState === NUMBER6){ // After E
n = buffer[i];
this.numberLength++;
if (n === 0x2b || n === 0x2d) { // +/-
if (n === 0x2d) { this.negativeExponent = true; }
this.tState = NUMBER7;
}
else if (n >= 0x30 && n < 0x40) {
this.exponent = this.exponent * 10 + (n - 0x30);
this.tState = NUMBER8;
}
else {
return this.charError(buffer, i);
}
}else if (this.tState === NUMBER7){ // After +/-
n = buffer[i];
this.numberLength++;
if (n >= 0x30 && n < 0x40) { // 0-9
this.exponent = this.exponent * 10 + (n - 0x30);
this.tState = NUMBER8;
}
else {
return this.charError(buffer, i);
}
}else if (this.tState === NUMBER8){ // * After digit (after +/-)
n = buffer[i];
this.numberLength++;
if (n >= 0x30 && n < 0x40) { // 0-9
this.exponent = this.exponent * 10 + (n - 0x30);
}
else {
if (this.negativeExponent) {
this.exponent = -this.exponent;
this.negativeExponent = undefined;
}
this.magnatude *= Math.pow(10, this.exponent);
this.exponent = undefined;
if (this.negative) {
this.magnatude = -this.magnatude;
this.negative = undefined;
} else if (this.tState === NUMBER1 || this.tState === NUMBER3) {
n = buffer[i];

switch (n) {
case 0x30: // 0
case 0x31: // 1
case 0x32: // 2
case 0x33: // 3
case 0x34: // 4
case 0x35: // 5
case 0x36: // 6
case 0x37: // 7
case 0x38: // 8
case 0x39: // 9
case 0x2e: // .
case 0x65: // e
case 0x45: // E
case 0x2b: // +
case 0x2d: // -
this.string += String.fromCharCode(n);
this.tState = NUMBER3;
break;
default:
this.tState = START;
var result = Number(this.string);

if (isNaN(result)){
return this.charError(buffer, i);
}

if ((this.string.match(/[0-9]+/) == this.string) && (result.toString() != this.string)) {
// Long string of digits which is an ID string and not valid and/or safe JavaScript integer Number
this.onToken(STRING, this.string);
} else {
this.onToken(NUMBER, result);
}

this.offset += this.string.length - 1;
this.string = undefined;
i--;
break;
}
this.tState = START;
this.onToken(NUMBER, this.magnatude);
this.offset += this.numberLength - 1;
this.numberLength = 0;
this.magnatude = undefined;
i--;
}
}else if (this.tState === TRUE1){ // r
if (buffer[i] === 0x72) { this.tState = TRUE2; }
else { return this.charError(buffer, i); }
Expand Down
9 changes: 6 additions & 3 deletions test/primitives.js
View file
Original file line number Diff line number Diff line change
Expand Up @@ -23,12 +23,14 @@ var expected = [
[ [], [ -1 ] ],
[ [ 0 ], -0.1 ],
[ [], [ -0.1 ] ],
[ [ 0 ], 6.019999999999999e+23 ],
[ [], [ 6.019999999999999e+23 ] ]
[ [ 0 ], 6.02e+23 ],
[ [], [ 6.02e+23 ] ],
[ [ 0 ], '7161093205057351174' ],
[ [], [ '7161093205057351174'] ]
];

test('primitives', function (t) {
t.plan(23);
t.plan(25);

var p = new Parser();
p.onValue = function (value) {
Expand All @@ -51,4 +53,5 @@ test('primitives', function (t) {
p.write('[0,1,-1]');
p.write('[1.0,1.1,-1.1,-1.0][-1][-0.1]');
p.write('[6.02e23]');
p.write('[7161093205057351174]');
});

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